1. Technical Field
The present invention relates to data processing systems, and further to a data processing system and method including a logical volume manager for storing a logical volume information. More particularly, the present invention relates to a data processing system and method including a logical volume manager for storing logical volume information at the top of each physical partition which is combined to create the logical volume.
2. Description of Related Art
IBM""s OS/2 operating system includes a function referred to as the Logical Volume Manager, or xe2x80x9cLVMxe2x80x9d. For systems without an LVM, each one of the physical partitions that is usable by the operating system is assigned a drive letter, such as xe2x80x9cC:xe2x80x9d or xe2x80x9cF:xe2x80x9d, producing a correlating drive letter for each physical partition on a disk in the computer system. The process which assigns these letters is commonly known. For systems with an LVM, a drive letter may be mapped instead to a logical volume which may contain one or more physical partitions. The process by which physical partitions are combined into a single entity is known generically as xe2x80x9caggregation.xe2x80x9d
It is necessary to have a storage area where LVM specific information is stored. This storage area must be accessible to only the LVM, and not to users. Further, the storage area must be located such that it would not prevent the disk drive from being shared with other operating systems.
The information stored in this storage area allows the LVM to re-create the volume every time the system is booted. Thus, the LVM allows groupings of physical partitions to appear to the operating system as a single entity with a single drive letter assignment.
An LVM offers various features, such as Bad Block Relocation, Drive Linking, Encryption, Software RAID, and Mirroring. These features represent a sample list of possible features, but in no way limits the number of types of features that could be made available. Bad Block Relocation is a method of reserving sectors and automatically remapping unwritable sectors to available reserved sectors. Drive Linking allows multiple partitions from one or more physical drives to be combined into one logical storage entity. Encryption provides a mechanism for encrypting user data on a partition or volume basis. Software RAID provides one or more levels of RAID support (i.e. RAID-0, RAID-5, etc.). Mirroring provides support to make a duplicate copy of a volume, either locally or remotely.
Thus, it would be beneficial to have an apparatus and method for storing logical volume information at the top of each physical partition which is combined to create the logical volume.
A data processing system and method are disclosed for storing logical volume information used by a logical volume manager to create and manage a logical volume. The data processing system includes a plurality of storage devices. A plurality of physical partitions within the plurality of storage devices are specified. Each one of the physical partitions includes a plurality of sectors. The specified physical partitions are logically combined to create the logical volume. A first plurality of the sectors are reserved in each of the physical partitions for the logical volume information. The first plurality of sectors are located at the top of each of the physical partitions. The logical volume information is stored in the first plurality of sectors in each of the physical partitions. In this manner, the logical volume information is stored at the top of each of the physical partitions.
Other features and advantages of the present invention will be described in, or will become apparent to those of ordinary skill in the art in view of the following detailed description of the preferred embodiments of the present invention.